Which circuit is used to detect FM-phone signals?

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Multiple Choice

Which circuit is used to detect FM-phone signals?

To recover audio from an FM signal, you need a circuit that converts changes in carrier frequency into a usable voltage. A frequency discriminator does exactly that: it outputs a voltage proportional to the instantaneous frequency deviation of the received FM carrier, which the audio stage then amplifies and plays back as sound. This is why it’s the appropriate detector for FM-phone signals. The other circuits serve different purposes. A balanced modulator is used to generate or process suppressed-carrier-modulated signals (commonly in AM/SUB-carrier contexts), not for FM demodulation. A product detector multiplies two signals to extract information from AM or SSB signals, which doesn’t translate frequency changes into audio for FM. A phase splitter simply divides a signal into two phase-shifted paths for balanced circuits, not for detecting modulation.

To recover audio from an FM signal, you need a circuit that converts changes in carrier frequency into a usable voltage. A frequency discriminator does exactly that: it outputs a voltage proportional to the instantaneous frequency deviation of the received FM carrier, which the audio stage then amplifies and plays back as sound. This is why it’s the appropriate detector for FM-phone signals.

The other circuits serve different purposes. A balanced modulator is used to generate or process suppressed-carrier-modulated signals (commonly in AM/SUB-carrier contexts), not for FM demodulation. A product detector multiplies two signals to extract information from AM or SSB signals, which doesn’t translate frequency changes into audio for FM. A phase splitter simply divides a signal into two phase-shifted paths for balanced circuits, not for detecting modulation.

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